Society in general continues to attach a stigma to hair loss. The desire for a healthy full head of hair has resulted in a variety of approaches to the "curing" of baldness. Among the multitude of hair growth studies that have been reported in the literature, several researchers have directed their study to the hair bulb. The hair bulb is a compact, elongate structure, located in the dermis, composed of three main cellular groups. The first comprises a compact group of fibroblasts known as the dermal papilla which includes a capillary system. The second group comprises germinative epithelial cells of the hair bulb which proliferate and differentiate to give rise to the mature hair shaft. The third group of fibroblasts exists around the outside of the bulb in the connective tissue sheath.
The dermal papilla is present as an aggregation of mesenchymal cells throughout the development of hair follicles in the embryo. The importance of the dermal papilla in hair growth and follicle induction in the adult has been demonstrated in a series of studies on the rat vibrissa follicle (see Oliver, R. F. "Whisker Growth After Removal of the Dermal Papilla and Lengths of the Follicle in the Hooded Rat" 15 Journal of Embryology and Experimental Morphology 331 (1966a); Oliver, R. F. "Histological Studies of Whisker Regeneration in the Hooded Rat" 16 Journal of Embryology and Experimental Morphology 231 (1966b)). It has been shown that surgical removal of the vibrissa follicle dermal papilla leads to a cessation of hair growth (see Oliver 1966a; Oliver 1966b; Oliver, R. F. "The Experimental Induction of Whisker Growth in the Hooded Rat by Implantation of Dermal Papillae" 18 Journal of Embryology and Experimental Morphology 43 (1967)). Resumption of hair growth in such follicles occurs when a new dermal papilla is regenerated or a new dermal papilla is implanted into the ablated follicle. The role of the dermal papilla in de novo follicle induction has been established in a series of recombination experiments in which rat vibrissa dermal papillae were combined with either glabrous ear or afollicular scrotal sac epidermas resulting in the formation of vibrissa-type follicles in the respective epidermal sheets (see Oliver, R. F. "The Induction of Follicle Formation in the Adult Hooded Rat by Vibrissa Dermal Papilla" 23 Journal of Embryology and Experimental Morphology 219 (1970)). Dermal papillae from hair follicles of a variety of species can be explanted in Vitro and give rise to distinctive populations of cells with characteristic behavioral and morphological properties (see Jahoda, C.A.B. and R. F. Oliver "The Growth of Vibrissa Dermal Papilla Cells In Vitro" 105 British Journal of Dermatology 623 (1981); Jahoda, C.A.B. and R. F. Oliver "Vibrissa Dermal Papilla Cell Aggregative Behaviour In Vivo and In Vitro" 83 Journal of Embryology and Experimental Morphology 81 (1984); Messenger, A.G. "The Culture of Dermal Papilla Cells From Human Hair Follicles" 110 British Journal of Dermatology 685 (1984); Withers, A.P., C.A.B. Jahoda, M. L. Ryder and R. F. Oliver "Culture of Wool Follicle Dermal Papilla Cells From Two Breeds of Sheep" 279 Arch. Dermatol. Res 140 (1984)). A remarkable property of the cells cultured from the dermal papillae of adult rat vibrissa follicles is the retention of the capacity to induce hair growth when introduced into the follicle cavities formed by the amputation of the lower halves of the follicle. (See Jahoda, C.A.B., K. A. Horne and R. F. Oliver "Induction of Hair Growth by Implantation of Cultured Dermal Papilla Cells" 311 Nature London 560 (1984); Horne, K. A., C.A.B. Johoda and R. F. Oliver "Whisker Growth Induced by Implantation of Cultured Vibrissa Dermal Papilla Cells in the Adult Rat" 97 Journal of Embryology and Experimental Morphology 111 ( 1986)). It has also been demonstrated that cultured papilla cells are capable of restimulating the growth of hair when introduced into follicles which have been rendered inactive as well as inducing morphogenesis of completely new hair follicles and the subsequent production of hair fibres. (Horne, K. A., C.A.B. Jahoda, R. F. Oliver and A. J. Reynolds, "Hair-Growth-Promoting Properties of Dermal Papilla Cells in the Rat" 380 Journal of Physiology (London) 48P (1986)).
U.S. Pat. No. 4,832,946, Green, issued May 23, 1989, assigned to Unilever, discloses a composition for topical application to mammalian hair or skin, comprising an amount of the cell-free supernatant from a culture of dermal papilla fibroblasts which increases hair growth in the rat by at least 10% more than that of a control composition.
German Patent DE 3 431 266, Birzer, published Mar. 6, 1986, discloses that external or internal administration of hair bulb cells with the papilla from slaughtered animals stimulates growth and genesis of hair and counteracts hair loss and hair greying. The cells are obtained from the hide of animals and can be applied internally by injection or as tablets or drops, and externally as shampoos, creams and soaps.
PCT Patent Application No. WO 85/04577, Bazzano, published Oct. 24, 1985 discloses a composition containing a pyrimidine carbamate which increases the rate of hair growth on mammalian skin, prolongs the growth phase of the hair growth cycle, and treats various types of alopecias.
U.S. Pat. No. 4,139,619, Chidsey, issued Feb. 13, 1979, assigned to the Upjohn Company, discloses a topical composition comprising Minoxidil and related iminopyrmidines which stimulates the conversion of vellus hair to terminal hair and increases the rate of growth of terminal hair.